feat: track API profile per session for per-profile stats (#32) (#38)

- Add Profile field to SessionRecord, populated with config.Default at scan time
- Add ByProfile map to DailyStat for per-profile cost aggregation
- Add ProfileCost struct and TopProfiles to Summary
- Add ProfileBreakdown() aggregator function
- Update Aggregate() to populate ByProfile data
- Add 'profile' view to TUI Stats tab f-key cycle (all→project→model→profile→all)
- Add aggregateByProfile() and rendering in stats_view.go

Author: ourines

internal/stats/aggregator.go

@@ -26,6 +26,7 @@ func Aggregate(records []SessionRecord, from, to time.Time) []DailyStat {
 				Date:      date,
 				ByProject: make(map[string]float64),
 				ByModel:   make(map[string]float64),
+				ByProfile: make(map[string]float64),
 			}
 			dailyMap[date] = ds
 		}
@@ -36,6 +37,11 @@ func Aggregate(records []SessionRecord, from, to time.Time) []DailyStat {
 		ds.OutputTokens += r.OutputTokens
 		ds.ByProject[r.Project] += r.CostUSD
 		ds.ByModel[r.Model] += r.CostUSD
+		profile := r.Profile
+		if profile == "" {
+			profile = "unknown"
+		}
+		ds.ByProfile[profile] += r.CostUSD
 	}
 
 	// Convert map to sorted slice
@@ -154,6 +160,28 @@ func ModelBreakdown(stats []DailyStat) []ModelCost {
 	return result
 }
 
+// ProfileBreakdown aggregates costs by API profile across all daily stats.
+// Returns a slice of ProfileCost sorted by cost descending.
+func ProfileBreakdown(stats []DailyStat) []ProfileCost {
+	totals := make(map[string]float64)
+	for _, s := range stats {
+		for profile, cost := range s.ByProfile {
+			totals[profile] += cost
+		}
+	}
+
+	result := make([]ProfileCost, 0, len(totals))
+	for profile, cost := range totals {
+		result = append(result, ProfileCost{Profile: profile, Cost: cost})
+	}
+
+	sort.Slice(result, func(i, j int) bool {
+		return result[i].Cost > result[j].Cost
+	})
+
+	return result
+}
+
 // GenerateSummary creates a comprehensive summary from session records.
 func GenerateSummary(records []SessionRecord, from, to time.Time) Summary {
 	dailyStats := Aggregate(records, from, to)
@@ -183,6 +211,7 @@ func GenerateSummary(records []SessionRecord, from, to time.Time) Summary {
 		CacheRead:      cacheRead,
 		TopProjects:    ProjectBreakdown(dailyStats),
 		TopModels:      ModelBreakdown(dailyStats),
+		TopProfiles:    ProfileBreakdown(dailyStats),
 		DailyBreakdown: dailyStats,
 	}
 }

internal/stats/scanner.go

@@ -91,6 +91,12 @@ func ScanSessions(opts ScanOptions) ([]SessionRecord, error) {
 		projects = make(map[string]config.ProjectEntry)
 	}
 
+	// Determine current default profile name
+	currentProfile := "unknown"
+	if cfg, err := config.LoadConfig(); err == nil && cfg.Default != "" {
+		currentProfile = cfg.Default
+	}
+
 	var records []SessionRecord
 
 	for _, entry := range entries {
@@ -126,7 +132,7 @@ func ScanSessions(opts ScanOptions) ([]SessionRecord, error) {
 			sessionID := strings.TrimSuffix(sf.Name(), ".jsonl")
 			filePath := filepath.Join(dirPath, sf.Name())
 
-			record, err := parseSessionFile(filePath, sessionID, projectAlias, projectPath)
+			record, err := parseSessionFile(filePath, sessionID, projectAlias, projectPath, currentProfile)
 			if err != nil {
 				continue // skip unparseable files
 			}
@@ -140,7 +146,7 @@ func ScanSessions(opts ScanOptions) ([]SessionRecord, error) {
 }
 
 // parseSessionFile reads a single JSONL session file and extracts a SessionRecord.
-func parseSessionFile(path, sessionID, project, projectPath string) (*SessionRecord, error) {
+func parseSessionFile(path, sessionID, project, projectPath, profile string) (*SessionRecord, error) {
 	f, err := os.Open(path)
 	if err != nil {
 		return nil, fmt.Errorf("open session file: %w", err)
@@ -151,6 +157,7 @@ func parseSessionFile(path, sessionID, project, projectPath string) (*SessionRec
 		SessionID:   sessionID,
 		Project:     project,
 		ProjectPath: projectPath,
+		Profile:     profile,
 	}
 
 	var (

internal/stats/types.go

@@ -7,6 +7,7 @@ type SessionRecord struct {
 	SessionID         string        `json:"sessionId"`
 	Project           string        `json:"project"`     // codes project alias (e.g. "codes"), falls back to path
 	ProjectPath       string        `json:"projectPath"` // full filesystem path
+	Profile           string        `json:"profile"`     // API profile name (config.Default at scan time), falls back to "unknown"
 	Model             string        `json:"model"`
 	StartTime         time.Time     `json:"startTime"`
 	EndTime           time.Time     `json:"endTime"`
@@ -28,6 +29,7 @@ type DailyStat struct {
 	OutputTokens int64              `json:"outputTokens"`
 	ByProject    map[string]float64 `json:"byProject"` // project alias -> cost
 	ByModel      map[string]float64 `json:"byModel"`   // model name -> cost
+	ByProfile    map[string]float64 `json:"byProfile"` // API profile name -> cost
 }
 
 // StatsCache is the on-disk cache of all scanned session data.
@@ -55,6 +57,7 @@ type Summary struct {
 	CacheRead      int64         `json:"cacheReadTokens"`
 	TopProjects    []ProjectCost `json:"topProjects"`
 	TopModels      []ModelCost   `json:"topModels"`
+	TopProfiles    []ProfileCost `json:"topProfiles"`
 	DailyBreakdown []DailyStat   `json:"dailyBreakdown"`
 }
 
@@ -69,3 +72,9 @@ type ModelCost struct {
 	Model string  `json:"model"`
 	Cost  float64 `json:"cost"`
 }
+
+// ProfileCost represents cost aggregation for a single API profile.
+type ProfileCost struct {
+	Profile string  `json:"profile"`
+	Cost    float64 `json:"cost"`
+}

internal/tui/stats_view.go

@@ -88,6 +88,8 @@ func (m Model) updateStats(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 		case "project":
 			m.statsBreakdown = "model"
 		case "model":
+			m.statsBreakdown = "profile"
+		case "profile":
 			m.statsBreakdown = "both"
 		}
 		return m, nil
@@ -186,6 +188,17 @@ func renderStatsView(daily []stats.DailyStat, records []stats.SessionRecord, tim
 		}
 	}
 
+	// By Profile breakdown
+	if breakdown == "both" || breakdown == "profile" {
+		profileCosts := aggregateByProfile(daily)
+		if len(profileCosts) > 0 {
+			b.WriteString(statsHeaderStyle.Render("  By Profile:"))
+			b.WriteString("\n")
+			renderBreakdown(&b, profileCosts, totalCost, barWidth, 8)
+			b.WriteString("\n")
+		}
+	}
+
 	// Daily trend chart
 	if len(daily) > 1 {
 		b.WriteString(statsHeaderStyle.Render("  Daily Trend:"))
@@ -195,7 +208,7 @@ func renderStatsView(daily []stats.DailyStat, records []stats.SessionRecord, tim
 
 	// Help footer
 	b.WriteString("\n")
-	breakdownLabel := map[string]string{"both": "all", "project": "project", "model": "model"}[breakdown]
+	breakdownLabel := map[string]string{"both": "all", "project": "project", "model": "model", "profile": "profile"}[breakdown]
 	help := fmt.Sprintf("  w:week  m:month  a:all  f:group(%s)  r:refresh", breakdownLabel)
 	b.WriteString(statsDimStyle.Render(help))
 
@@ -228,6 +241,16 @@ func aggregateByModel(daily []stats.DailyStat) []costEntry {
 	return sortedEntries(totals)
 }
 
+func aggregateByProfile(daily []stats.DailyStat) []costEntry {
+	totals := make(map[string]float64)
+	for _, d := range daily {
+		for profile, cost := range d.ByProfile {
+			totals[profile] += cost
+		}
+	}
+	return sortedEntries(totals)
+}
+
 func sortedEntries(m map[string]float64) []costEntry {
 	entries := make([]costEntry, 0, len(m))
 	for name, cost := range m {